Teleportation of two-particle entangled state via
an asymmetric state
*
Chen Xiu-Bo(陈秀波)
a)
, Wen Qiao-Yan(温巧燕)
a)
and Zhu Fu-Chen(朱甫臣)
b)
a) State key Laboratory of Networking and Switching Technology, Beijing University of
Posts and Telecommunications, Beijing 100876, China
b) National Laboratory for Modern Communications, P.O.Box 810, Chengdu, 610041, China
We propose a protocol for three-party quantum teleportation via a asymmetric triplet in an
entangled state, which is much more valuable than GHZ and W state for some applications in quantum
information processing. In the protocol, quantum information of an unknown two-particle entangled
state, namely, the quantum state itself, is transmitted from the sender to the remote receiver with the
aid of the co-sender. It is found that by means of optimal discrimination between two nonorthogonal
quantum states, the protocol of teleportation can be realized probabilistically. In addition, all kinds of
transformations performed by the sender and the receiver are given in detail.
Keywords: teleportation, two-particle entangled state, three-particle asymmetric state,
generalized measurement
PACC: 0365, 0367
1 Introduction
In the burgeoning field of quantum information processing, scientists have made dramatic
progress with quantum cryptography and quantum teleportation, which are two important quantum
communication schemes, in theory and experiment
[1-4]
. Quantum cryptography can ensure the
security of the key distribution, and thus realize the confidential transmission of classical
information under the nose of eavesdropper, regardless of her computing power or technological
sophistication. Quantum teleportation, which has been considered to be one of the striking nontrivial
techniques, allows for the transmission of quantum information to a distant location via a quantum
channel with the help of local operation and classical communications (LOCC).
Since the seminal work of Bennett et al
[3]
in 1993, quantum teleportation has been paid much
attention due to its important applications in quantum communication and quantum calculation. At
present, various kinds of quantum teleportation have been proposed
[5-22]
.
As far as pure three-qubit
states is concerned, it has been proved that
[23]
three entangled qubits can be classified into two
inequivalent classes, such as GHZ-type and W-type which are all symmetric three-particle states,
under stochastic local operations and classical communication (SLOCC) transformations. It has been
shown that, when the three-particle GHZ state is shared as quantum channel
[5]
, the fidelity of
teleportation is
2/3 (sin(2 ))/3
GHZ
F
〈〉=+ and when the three-particle W state is utilized
[6]
, the
*
This work is supported by the National High Technology Research and Development Program of China, Grant No.
2006AA01Z419; the Major Research Plan of the National Natural Science Foundation of China, Grant No. 90604023;
the National Laboratory for Modern Communications Science Foundation of China, Grant No. 9140C1101010601;
and the Natural Science Foundation of Beijing, Grant No. 4072020.
http://www.paper.edu.cn